DIY Mobile Stage ideas

I'm working on a mobile stage as I've been asked to help with several cancer society gigs here in the US, and there's no real affordable staging in the area. Plans are to build enough 4x8 modules for a 24' x 16' stage with an 8' x 8' drum riser. Nothing professional grade, something for smaller festivals and such, and eventually will be adding a canopy to it. Looking at 3/4" sheets of plywood (4' x 8'), 2x4 frame around & across middle, with 2x4 legs (or possibly 2 pieces of 2x4) for 18" stage height, 4" bolts to hold legs vertical & to hold pieces of staging together.

This is a budget build, but I still want something functional and nice. And yes, I know about the complaints as far as insurance concerns and liability, I have plans to have that worked out. Just looking for "constructive" criticism (bad pun, lol). Thanks!

A DIY job would be easy, using wood and construction 3/4" plywood. Making foldable legs is also no problem. The real problem will be with the weight of the whole thing. The way you plan on doing it, nobody will be able to lift any of the elements!

If cost is an issue, I would make up steel frames with legs that slot into the frame and have each frame the exact size of a sheet of 3/4" ply. (Get the welder out!) You could also buy some old scaffolding on ebay and cut it down to size.

Failing that, there are pleanty of small companies building portable staging -

The Red Bladder wrote:A DIY job would be easy, using wood and construction 3/4" plywood. Making foldable legs is also no problem. The real problem will be with the weight of the whole thing. The way you plan on doing it, nobody will be able to lift any of the elements!

If cost is an issue, I would make up steel frames with legs that slot into the frame and have each frame the exact size of a sheet of 3/4" ply. (Get the welder out!) You could also buy some old scaffolding on ebay and cut it down to size.

Failing that, there are pleanty of small companies building portable staging -

For the price of one section of that I can have a 16x8 stage..or bigger..lol. If i knew how to weld, metal would help with structure and such. It will be a bit heavy, but I'm thinking of adding castors to the legs for when they're in place...should ease moving them around some on flat surfaces. Still playing with ideas, going to go get a sheet and some wood tomorrow and find the best solution.

UK theatrical practise for a long time was to build things called 'gate leg rostra', usually with 18mm ply tops, and 3*1 pine frames and legs (not as lethal as it sounds, given the way they work). The advantage is that the frames fold up, and due to clever structural design are somewhat lighter then a simpler design. There should be drawings in any good book on scenic carpentry.

For the US, you may wish to obtain a copy of "Structural design for the stage", which includes some designs for US style rostra, for the UK, "Temporary demountable structures" is the book.

Fire codes, Building codes, rider acceptability... And the sheer amount of time to build enough of the damn things, let alone the pain involved in setting them up on site makes me think this is a bad idea, but it is your decision.

One thing you should NOT touch designing is any sort of roof structure or rigging, that goes horribly wrong often enough even when designed and erected by professionals.

dmills wrote:Fire codes, Building codes, rider acceptability... And the sheer amount of time to build enough of the damn things, let alone the pain involved in setting them up on site makes me think this is a bad idea, but it is your decision.

+1 completely!

Some simple observations -

1. 3/4" ply has to be supported every 40cm or 18" and you CANNOT have a 4 x 8 sheet with only one leg at each corner! No matter how much bracing you put under it, it will fail when the first person dares to jump up and down. (And that would be a normal person - have you seen the size of some people lately!!??)

2. Given correct numbers of legs, braces and supports, your total structure would weigh at least 2.5 tons! Vehicle? And assuming that 2x4 still costs between 50 Cents a $1 a foot (wood yard or retail) your whole construction could set you back $3,500!!! (Those 'pro' systems are not looking so expensive after all!)

3. Each element would be too heavy for two people to carry and would have to be wheeled in - and not every venue is step-less, elevator-less and with wide doors. Four strong men could carry one element (just) but you can't get four men around an upright element going through a door frame or up a flight of stairs!

4. Yesterday, I built a scaffolding platform with 3/4 ply and 2x4. Each element was 5' by 18" and that is the most one man can comfortably carry repeatedly - and I am a big and strong bloke with no fat, 6'2" and 200 US lbs.

5. You can still use the cheap 3/4" ply as flooring, but what goes on underneath has to be properly and professionally built and you may need safety certification for some venues - best check in advance. Ebay is full of stage construction companies that can help you.

ronmac wrote:There are certain aspects of any project that DIY isn't the best option. This is one of them.

+1 to that. And +1 again.

Always leave stage-building to the professionals, your PL insurance will not cover you if you even attempt to build something like this, and certainly in the UK you'd be personally liable should your insurance be declared invalid.

Yeah, it's a risky idea but this is temporary until I can purchase some fold up staging. There's another guy that has a stage rig that is basically the same thing they use downtown all the time. Does anyone have an idea of some companies that produce cheap fold-up staging, but still stable, in the US?

I guess a lot of this stuff is made in China so if it's available here in the UK it's almost certainly available in the US too. I'd add my voice to the chorus shouting 'no' to home-made staging - we did lots when I was at school 40 years ago but it just isn't viable nowadays - people are heavier, situations are more demanding and the onus is on the provider rather than the user to be safe.

You have a lot of work to do whichever route you go, but the hard work is educating clients that all this stuff costs money to buy or hire and it has to be done safely and controllably. To me, that's the challenge. You can sell anything if it's free, but you have to get people to put a value on safetly, reliability and everything else you get when you use the proper product.

While you're saving up for the full stage, get some staging the height you want your normal stage to be but the size for the drum riser - then you can use it as part of the main stage later and deal with the drum riser as you originally planned. Only having the drums up is not ideal, but it sure looks more like a stage than having everything on the floor. Or you could make it into a long narrow platform to raise the back row a bit where that's an appropriate solution - a big band, say. Lots of possibilities if, excusing the pun, you think out of the box.

Dan as usual is dead on in his reply and worth reading multiple times. While I may disagree with it being worth the time and effort or not, everything else he says is dead on.

1. 3/4" ply has to be supported every 40cm or 18" and you CANNOT have a 4 x 8 sheet with only one leg at each corner! No matter how much bracing you put under it, it will fail when the first person dares to jump up and down. (And that would be a normal person - have you seen the size of some people lately!!??)

Sorry you are absolutely wrong here. Keeping in mind safety code in your area has to apply...

You DO have to be careful of certain things, for instance the weight of the platform needs to rest on the bracing, not on the plywood top. And you can support every 2', but I wouldn't go over 2' in most cases, but I can assure you, I have several pieces of platforming of various sizes up to 4x8 and legged (Or castered) at the corners, and yes multiple people could jump on (And have as I use them for rock shows) without issue. In this case the bracing is done with 2x10s, which is obviously much more structural than 2x4s, but my point in general stands as you stated 'No matter how much bracing'. You could certainly do it with smaller bracing (And in fact I have in the past).

2. Given correct numbers of legs, braces and supports, your total structure would weigh at least 2.5 tons! Vehicle? And assuming that 2x4 still costs between 50 Cents a a foot (wood yard or retail) your whole construction could set you back ,500!!! (Those 'pro' systems are not looking so expensive after all!)

3. Each element would be too heavy for two people to carry and would have to be wheeled in - and not every venue is step-less, elevator-less and with wide doors. Four strong men could carry one element (just) but you can't get four men around an upright element going through a door frame or up a flight of stairs!

I believe your math is off here. I do stagehand work as well as my sound engineering/design/consulting and end up loading in a lot of platforming depending on the show, including 4x8 platforms very similar to what is described above, and can assure you that any two stagehands can carry a 4x8/2by4(And often larger bracing) platform with no issue. 2.5 tons seems quite high as well for that size of stage.

Looking at this:
Figuring approx. 100lbs for each platform (Which honestly sounds high, but going off the math and looking up wieghts in the Backstage Handbook) a 4'x8' braced with 2x4's around all sides and every 2 feet.
24x16 stage is 12 platforms
8x8 drum riser is 2 platforms

14 x 100lbs == 1400lbs, or 3/4 ton, not 2.5 tons.

Even with 18" legs of 3qty 2x4s at each corner and another set of 2 in the middle (Standard practice although 2qty 2x4s is more standard across the board) you have added 36 lbs to the overall weight (A little under actually but I rounded down above) of each platform for a total of about 140lbs alltogether accounting for the rounding I did above.

14 x 140lbs == 1960lbs, or just under a ton.

Now those 2x10 platforms I mentioned above weigh about 200lbs each so end up being about the 2.5 tons for that size of deck yes, but are also overkill for many things unless you plan on rolling around genie lifts etc. on the deck, in which case you should be going with at least double thickness 3/4" ply as that is a lot of weight on very small points.

And finally legging, while it is done, as mentioned above isn't really the best way to handle platforming, which really you should be using trussing under the platforming to support on the bracing. But see Dan's comments in general for better ways, structural design for the stage is a great book to read through in general when dealing with anything like this (Which reminds me I need to re-read it sometime). And honestly I tend to agree with Dan in that for most thigns this isn't worth the effort. In some occasions it is, but mostly it is not. Rent in the staging when you need it, honestly.

Again make sure you check all applicable codes for your area.

5. You can still use the cheap 3/4" ply as flooring, but what goes on underneath has to be properly and professionally built and you may need safety certification for some venues - best check in advance. Ebay is full of stage construction companies that can help you.

@ Seablade - you are of course absolutely right! I just did a back of envelope calculation and without even getting off the pot on 40cm per joist and extra legs and diagonal bracing, I came to almost exactly the same figure as you. I have no idea what I was thinking and I can only assume that the envelope I was using the back of, must have been defective!

But on a slightly more serious note, the guy, i.e. the OP, wants to rent these stage elements out as a commercial venture (according to his own website) and means that his structure will have to carry public liability insurance and quite honestly, I very much doubt that any insurance company will pay out even a dime on a DIY'ed structure on the event of a claim. They think in terms of things like as large a crowd of really fat people as can fit on that stage, all doing the pogo together - and therefore take a very po-faced view of life!

Also, I very much doubt that any sane person would want to hire such a structure.

The Red Bladder wrote:But on a slightly more serious note, the guy, i.e. the OP, wants to rent these stage elements out as a commercial venture (according to his own website) and means that his structure will have to carry public liability insurance and quite honestly, I very much doubt that any insurance company will pay out even a dime on a DIY'ed structure on the event of a claim. They think in terms of things like as large a crowd of really fat people as can fit on that stage, all doing the pogo together - and therefore take a very po-faced view of life!

Also, I very much doubt that any sane person would want to hire such a structure.

While I don't agree with the business plan if that is the plan as I would always go for the higher quality and lighter staging myself, I can tell you I have enough shows come through using similar systems for corporate and other gigs that I suspect the insurance can be obtained on this side of the pond without to much difficulty.

I appreciate the input guys. Yes, it sounds like a risky move, and it sounds awfully hazardous, but this is a temporary staging, mostly for indoor work (it will see maybe 1-2 outdoor shows as most I do are at some form of main stage) and as stated before, there's not going to be a whole lot on it in general. I plan to buy something similar to the Intellistage setup, but that's in the plans when things pick up here. I've actually thought about shortening the leg height to 12-16" for a more stable platform. Like I said, it's a temporary fix, and the City actually has a stage similar (except with 5/8" ply and a fixed leg structure). I'm still debating on it, but I am hoping to purchase something soon for a more reliable rig.

You seriously need a copy of "Structural design for the stage", the stress skin panel designs will probably be worth the price of admission for you.

Whatever you do, please do NOT even think about any sort of roof over the thing, they are tricky and accidents are common even when designed and erected by professionals. Wind and weather loads can cause structural failure very, very easily, and that if before we even touch hanging anything off it. There is a reason stages with roofs cost what they do to hire. Do some googling, there are plenty of pictures of stage roof collapses, and there have been more then a few deaths, you do NOT want to go there.

dmills wrote:You seriously need a copy of "Structural design for the stage", the stress skin panel designs will probably be worth the price of admission for you.

Whatever you do, please do NOT even think about any sort of roof over the thing, they are tricky and accidents are common even when designed and erected by professionals. Wind and weather loads can cause structural failure very, very easily, and that if before we even touch hanging anything off it. There is a reason stages with roofs cost what they do to hire. Do some googling, there are plenty of pictures of stage roof collapses, and there have been more then a few deaths, you do NOT want to go there.

Regards, Dan.

Agreed on both counts. Stress Skin designs are all sorts of awesome when it comes to making things lighterweight and durable, though making them properly can be tricky unless you have the right tools and some experience, it requires a bit more forethought and planning than standard flats.

And yes anything over people's heads is an entire different ball of wax and has been in the news a lot lately. Just google Indiana State Fair Stage, and you w ill see what I mean, it isn't pretty.

dmills wrote:You seriously need a copy of "Structural design for the stage", the stress skin panel designs will probably be worth the price of admission for you.

Whatever you do, please do NOT even think about any sort of roof over the thing, they are tricky and accidents are common even when designed and erected by professionals. Wind and weather loads can cause structural failure very, very easily, and that if before we even touch hanging anything off it. There is a reason stages with roofs cost what they do to hire. Do some googling, there are plenty of pictures of stage roof collapses, and there have been more then a few deaths, you do NOT want to go there.

Regards, Dan.

Agreed on both counts. Stress Skin designs are all sorts of awesome when it comes to making things lighterweight and durable, though making them properly can be tricky unless you have the right tools and some experience, it requires a bit more forethought and planning than standard flats.

And yes anything over people's heads is an entire different ball of wax and has been in the news a lot lately. Just google Indiana State Fair Stage, and you w ill see what I mean, it isn't pretty.

Seablade

I remember that incident. If anything, at most I would get some collapsable canopies just to hide everyone from the shade. They make some 8x10 canopies for $89 here.

Seablade and Dan are trying to protect you from making a dreadful mistake. Just ask yourself, can your DIY'ed wooden structure with four legs take 16 or 20 middle-aged and fat Hells Angels all pogoing and throwing beer over one another? That is considerably more strain than parking a pick-up truck on it - and a VERY usual thing to happen at a party rental.

And at the same time, children just love to crawl about under a stage. Think about it!

Please note - Normal stage elements are built to take 750 kgs per sq m - at least, that is the legal requirement for any floor in a temporary building (e.g. a stage) in most European countries.

On a business note - your DIY'ed structure will cost you almost as much as a brand-spanking-new stage element. Here, in the UK, there are several dealers in used show equipment and you can buy anything from a stage to a circus tent. I am sure you will have such companies where you are.

The Red Bladder wrote:Seablade and Dan are trying to protect you from making a dreadful mistake. Just ask yourself, can your DIY'ed wooden structure with four legs take 16 or 20 middle-aged and fat Hells Angels all pogoing and throwing beer over one another? That is considerably more strain than parking a pick-up truck on it - and a VERY usual thing to happen at a party rental.

And at the same time, children just love to crawl about under a stage. Think about it!

Please note - Normal stage elements are built to take 750 kgs per sq m - at least, that is the legal requirement for any floor in a temporary building (e.g. a stage) in most European countries.

On a business note - your DIY'ed structure will cost you almost as much as a brand-spanking-new stage element. Here, in the UK, there are several dealers in used show equipment and you can buy anything from a stage to a circus tent. I am sure you will have such companies where you are.

And now you really want to put a roof over it? Dear God, man!

Not for this staging, this is going to be bands and small performing acts only. It's going to be 4 legs per 4x4 section, which means 8 legs on a 4x8 sheet, with considerable framing and structural integrity. The only difference is the legs will be hinged, but bolted when in use (several lag bolts per leg) for mobility's sake. The most one piece is ever going to see is an amp rack, but it will be sitting directly on legs taking the most force, not in the middle, and the "floor" will be coated with some sort of spray-on liner to help structurally. Oh, and just figured I'd mention this, the bar I work at has a 12x8 variation of this stage that I'm sitting on right now, and it's holding up fine (except it's about an 8-12" height.

Mike Sullivan wrote:Not for this staging, this is going to be bands and small performing acts only. It's going to be 4 legs per 4x4 section, which means 8 legs on a 4x8 sheet, with considerable framing and structural integrity. The only difference is the legs will be hinged, but bolted when in use (several lag bolts per leg) for mobility's sake. The most one piece is ever going to see is an amp rack, but it will be sitting directly on legs taking the most force, not in the middle, and the "floor" will be coated with some sort of spray-on liner to help structurally. Oh, and just figured I'd mention this, the bar I work at has a 12x8 variation of this stage that I'm sitting on right now, and it's holding up fine (except it's about an 8-12" height.

You should re-read what I wrote above. While you CAN do one set of legs on each corner, you SHOULD leg in the middle as well, and have plenty of crossbracing, especially with 2x4 framing.

And when you say 'The most one piece is ever going to see is an amp rack' you need to be VERY sure on exactly how much weight is being put on any single point, and make sure the entire stage can take at a minimum 2x that weight on any given point. When you are dealing with amp racks, some of the heaviest on the sound world side of things, you are also talking about all that weight being put on 4 very small areas, which you will not be able to put over each leg, nor will you be able to prevent from rolling over the rest of the stage, and of course if it rolls chances are it will have other things stacked on it, people sitting on it, etc. And all that weight will get distributed to points that are likely around 1 inch square, that your playwood has to be able to support.

Bars are not known for doing things the right way for the record, just the cheap way.

Mike Sullivan wrote:Not for this staging, this is going to be bands and small performing acts only. It's going to be 4 legs per 4x4 section, which means 8 legs on a 4x8 sheet, with considerable framing and structural integrity. The only difference is the legs will be hinged, but bolted when in use (several lag bolts per leg) for mobility's sake. The most one piece is ever going to see is an amp rack, but it will be sitting directly on legs taking the most force, not in the middle, and the "floor" will be coated with some sort of spray-on liner to help structurally. Oh, and just figured I'd mention this, the bar I work at has a 12x8 variation of this stage that I'm sitting on right now, and it's holding up fine (except it's about an 8-12" height.

You should re-read what I wrote above. While you CAN do one set of legs on each corner, you SHOULD leg in the middle as well, and have plenty of crossbracing, especially with 2x4 framing.

And when you say 'The most one piece is ever going to see is an amp rack' you need to be VERY sure on exactly how much weight is being put on any single point, and make sure the entire stage can take at a minimum 2x that weight on any given point. When you are dealing with amp racks, some of the heaviest on the sound world side of things, you are also talking about all that weight being put on 4 very small areas, which you will not be able to put over each leg, nor will you be able to prevent from rolling over the rest of the stage, and of course if it rolls chances are it will have other things stacked on it, people sitting on it, etc. And all that weight will get distributed to points that are likely around 1 inch square, that your playwood has to be able to support.

Bars are not known for doing things the right way for the record, just the cheap way.

Seablade

If you would have read my post before, I did mention it has 8 legs total, 2 on each end and 4 in the middle...And no, not an amp rack, I'm talking about actual amplifiers.

Mike Sullivan wrote:If you would have read my post before, I did mention it has 8 legs total, 2 on each end and 4 in the middle...And no, not an amp rack, I'm talking about actual amplifiers.

You are correct in that you did say 8 legs and I misread, but you also did say amp rack:) All my previous comments still apply.

Seablade

The only amps that would be going on stage would be the guitar amps.

I built a prototype stage with a 5/8" sheet of plywood, 2x4 frame & legs, and it actually came out REALLY well. 14x3" screws all around, and no stability issues. Going to build the second one to the full stage specifics, lag bolts and all. Hoping to try 2 bolts in each leg, one in each direction.

Pictures are from Facebook.

Both me and my father stood on it, jumped around, everything, and no issues. I think this will work temporarily.